Hey there. Hop inside my Villain-O-Matic?

They have to have a purpose for being mean and what there doing. They also (mostly likely) need to b very unlikable.

BQ: He's greedy and wants to take advantage of this girl with all this power and nearly kills her.

BQ2: Kinda depends on the story. In my story, no. Ive seen in others were it works tho. Like a bitter sweet ending?

I think that you should add character depth to any villain. Giving them a back story to explain their why thy are evil is always nice. Sometimes they can be a pure sociopath (can't feel love or remorse). People are mainly motivated by: money/power/greed/love/survival. So those are all the motivations as far as motives. I think the an evil antagonist should have more bad qualities than good, but still have some good. A few traits are usually: they easily hate and judge people, they have a quick temper that they hide behind a cool exterior and a loyal group of followers.

BQ: The Covenant is the government that encourages discrimination between the 4 main groups, as well as hates people who are mixed. They try to stay in power by arranging marriages. Often they kill people who are trying to rise against them. (Watch out, they know everything!)

BQ2: I guess sometimes. Usually it's only because that makes a shocking ending. However if it was a series I would be a little put out if the bad guy won. (Unless of course he was really the good guy the entire time.)

Hope that helped.

The antagonist must have a reason why they are doing what they are doing, and it has to make sense within the context of their motivation to be after the goal they seek.

Bq: Venus is a parasitic plant-monster whose only desire is to consume living beings.

Bq2: Sure, sometimes. >:3